xStack
® 
DGS-3120 Series Managed Switch CLI Reference Guide 
300 
 
that the system received a ARP request packet that is sent by an IP address that match the 
system’s own IP address. In this case, the system knows that some body out there uses an IP 
address that is conflict with the system. In order to reclaim the correct host of this IP address, the 
system can send out the gratuitous ARP request packet for this duplicate IP address. 
 
Format 
config gratuitous_arp send dup_ip_detected [enable | disable] 
 
Parameters 
enable - Enable sending of gratuitous ARP when duplicate IP is detected. 
disable - Disable sending of gratuitous ARP when duplicate IP is detected. 
 
Restrictions 
Only Administrator, Operator and Power-User level users can issue this command. 
 
Example 
To enable send gratuitous ARP request when duplicate IP is detected: 
DGS-3120-24TC:admin# config gratuitous_arp send dup_ip_detected enable 
Command: config gratuitous_arp send dup_ip_detected enable 
 
Success. 
 
 
32-3  config gratuitous_arp learning 
Description 
This command is used to configure gratuitous ARP learning. Normally, the system will only learn 
the ARP reply packet or a normal ARP request packet that asks for the MAC address that 
corresponds to the system’s IP address. The command is used to enable/disable learning of ARP 
entry in ARP cache based on the received gratuitous ARP packet. The gratuitous ARP packet is 
sent by a source IP address that is identical to the IP that the packet is queries for. Note that, with 
the gratuitous ARP learning, the system will not learn new entry but only do the update on the ARP 
table based on the received gratuitous ARP packet. By default, the state is disabled status. 
 
Format 
config gratuitous_arp learning [enable | disable] 
 
Parameters 
enable - Enable learning of ARP entry based on the received gratuitous ARP packet. 
disable - Disable learning of ARP entry based on the received gratuitous ARP packet.